Doesn't really matter what he did before or how much he knows.
There is no valid reason for a salesperson to make stuff up, or to insult the horse you rode in on.
Like I said, take the 15 minutes to write a polite letter and mail two copies, one to the GM and/or Sales Manager, and a "courtesy copy" to the salesguy explaining that you don't expect him to know everything, but you DO expect that everything he tells you is 100% true and accurate.
Close with you don't really appreciate being insulted about the car you drove to the dealership.
Tell him it makes you suspicious when the guy spends time running down your car when he should be selling the new car. It makes you wonder if he's trying to hide something about the new car by changing the subject to cutting down the trade.
TB
